钼蓝分光光度法测锌及锌合金中硅量方法改进

摘要

The paper analyzes molybdenum blue spectrophotometric method that is used to measure silicon content in zinc and zinc alloy, meanwhile, researches some shortcomings and gives some supplements and advices. The new method uses matrix matching to correct standard curve and the blank by eliminating the matrix interference. Color range pH5.6 ~ 7.6 is used on nitrophenol to adjust pH. Experiments show that silicon and ammonium molybdate react to generate silicon molybdenum heteropoly acid in sulfuric acid medium by using ascorbic acid as reducing agent. The concentration of silicon standard solution within 0 ~ 1.0 μg/mL conforms to beer's law, standard recovery is 98% ~ 101%, which is better than the national standard method and broaden the scope of determination of silicon content.%对国标中用于测定锌及锌合金中硅含量的钼蓝光度法进行了分析,研究了其中的不足,并作出了几点补充和建议.新方法采用基体匹配方式校正标准曲线及空白,消除基体干扰;使用变色范围pH5.6~7.6的对硝基苯酚调pH.实验表明:在硫酸介质中,硅与钼酸铵生成硅钼杂多酸,用抗坏血酸作还原剂,硅标准溶液浓度在0~1.0 μg/mL范围内符合比尔定律,标准回收率为98%~101%,较国标方法更理想,拓宽了硅量测定范围.